COMPARISON BETWEEN THE DOUBLE BUFFER METHOD AND THE EQUIVALENT RECTANGLE METHOD FOR THE QUANTIFICATION OF DISCREPANCIES BETWEEN LINEAR FEATURES

• Published in: Boletim de Ciências Geodésicas 2018-07, Vol.24 (3), p.300-317
• Main Authors: França, Leandro Luiz Silva de, Silva, Luiz Felipe Coutinho Ferreira da
• Format: Article
• Language: English
• Subjects: Accuracy; Buffers; Cartography; Digital mapping; Equivalence; GEOCHEMISTRY & GEOPHYSICS; Geography; Homology; Mapping; Open systems; Polygons; Quality standards; REMOTE SENSING; Roads & highways
• ISSN: 1413-4853; 1982-2170; 1982-2170
• DOI: 10.1590/s1982-21702018000300020

Abstract Currently, in Brazil, for the assessment of the Positional Accuracy of non-point features (lines and polygons), there is no standard norm of execution. This work aims to compare the results of two methodologies that allow determining the average value of the discrepancies between linear features. The first, Equivalent Rectangle Method, aims to determine the discrepancy by considering an equivalent rectangle for the polygon obtained from the two homologous lines. The second, Double Buffer Method applies a buffer on both lines and obtains the average discrepancy value based on the relation of the areas of the generated polygons. These methods were compared in two steps. Initially, an experiment was performed with features of known measurements, where the displacement of the homologous lines was controlled in azimuth and distance. In this step, it was verified that the shape of the feature and the direction of the displacement interfere in the results of both methods when compared to the traditional procedure of measurement of discrepancies by homologous points. In the second stage, we evaluated the vector data of the OpenStreetMap (class of roads), with reference to a more accurate vector dataset produced for the Mapping of the State of Bahia. As a result, for the 1:25,000, 1:50,000, 1:100,000 and 1:250,000 scales, it was obtained, respectively, the PEC-PCD for the Equivalent Rectangle Method "C", "B", "A" and "A" and the PEC-PCD for the Double Buffer Method "R", "C", "B" and "A", where "R" means that it has not achieved the minimum PEC-PCD classification. Resumo Atualmente, no Brasil, para a avaliação da Acurácia Posicional de feições não pontuais (linhas e polígonos), não existe uma norma padrão de execução. Este trabalho tem como objetivo comparar os resultados de dois métodos que permitem determinar o valor médio das discrepâncias entre as feições lineares. O primeiro, Método do Retângulo Equivalente, visa determinar a discrepância considerando um retângulo equivalente para o polígono obtido a partir de duas linhas homólogas. O segundo, Método do Buffer Duplo, aplica um buffer nas duas linhas e obtém o valor de discrepância média baseado na relação das áreas dos polígonos gerados. A comparação dos métodos foi realizada em duas etapas. Inicialmente, foi realizada uma experimentação com feições de medidas conhecidas, onde o deslocamento das linhas homólogas foi controlado em azimute e distância. Nessa etapa verificou-se que a forma da feição e a d